“This notion of content being here and commerce being there doesn’t really exist any more. Everyone has become a publisher,” Lerer Ventures partner and former Huffington Post CEO Eric Hippeau said Tuesday at Group Commerce’s Think Commerce conference in New York.

But, as content and commerce merge, he added that “it’s a lot easier for commerce brands to become publishers… than it is for people on the media side to add commerce.”

Historically, publishers have respected the line between “church and state,” separating editorial content from advertising and commercial content. Even Condé Nast’s Lucky fashion magazine, which is perfectly positioned for commerce, has not made the transition, he said. (Although the recently-launched iPad app does include direct links to products.)

And, it’s easy to understand why that bridge is difficult to cross. In addition to the cultural resistance against compromising an editorial identity with a commercial interest, e-commerce involves creating a whole new business model, with potentially new margin structures, customer service needs and other requirements.

How much credibility can commerce companies earn?

Interestingly, however, Philippe von Borries, co-founder of fashion and beauty site Refinery29 recently told Pandodaily that he thinks it’s commerce companies who have more challenges crossing over into publishing. “No one gives a shit about content from a commerce company,” he said, explaining that his is a media company that uses content to drive its commerce business. While media companies come from a place of credibility, he believes that any content from commerce companies will only be viewed as a kind of sophisticated marketing.

But while it’s true that a customer may never look to Warby Parker or Gilt Groupe for a position on, say, the fiscal cliff, it doesn’t mean that commerce companies can’t be credible purveyors of content within the verticals on which they focus. And, as Hippeau said, as social platforms turn everyone into some kind of publisher, the definition of “content” itself is changing, in turn altering what it means to be in the media business.

Thrillist: we’ve turned readers into buyers and vice versa

One company leading the way in the new world of content-meets-commerce is Thrillist and, at the Think Commerce conference, Ben Lerer, the company’s co-founder and CEO, said that more than half of Thrillist’s nearly $70 million annual revenue comes from Jack Threads, the e-commerce site it purchased in 2010.

“We’ve proven that we can turn a reader into a buyer,” he said. “We’re pleased that we can also turn a buyer into a reader.”

But despite Thrillist’s own success, he acknowledged not all media companies are as well positioned to cross into commerce. From its launch, Thrillist’s value proposition was a site that recommended ways in which young men should spend their time – an ideal starting point for a commercial relationship. But news and sports publishers, even those with engaged audiences, may have a more difficult time with commerce because their content isn’t recommendation or action oriented.

Shana Fisher, managing partner at High Line Venture Partners, said that while it can be tricky to focus on two revenue streams at once and that companies initially supported by advertising revenue (like nearly all media companies) may find it difficult to later ask customers for credit card information, more companies should blend revenue strategies based on content and commerce.

“In verticals that are transactional, the divide is really small,” she said, highlighting food and fashion. “If it’s not related to something that’s transactional, it’s more abstract.”